Influence of weather on population fluctuation of Phytophthora capsici, flushing and feeder root production in black pepper

摘要

Phytophthora capsici (Leonian 1922, emend A.Alizadeh and P.H.Tsao) infects black pepper (Piper nigrum L.) during the wet monsoon period. During the inter-monsoonal dry period the fungus remain dormant in the soil. At the onset of monsoon when soil moisture builds up, the activity of P. capsici is resumed. This period also trigger the production of feeder roots and fresh foliage. Availability of tender susceptible tissues and a congenial weather favours the rapid spread of the disease during monsoon.